Heat oil in a large soup pot over medium-high heat. Add sausage and shallots then saute until sausage begins to brown, 3-4 minutes. Add sweet corn then saute for 2 minutes. Sprinkle in 2-1/2 teaspoons Old Bay seasoning then saute for 30 more seconds.

Add chicken broth then turn heat up to high and bring to a boil. Add potatoes then turn heat down to medium and simmer until potatoes are tender, 10-15 minutes. Add shrimp then remove pot from heat, place a lid on top, and let shrimp cook through, 3-4 minutes. Taste then add up to 1/2 teaspoon more Old Bay if needed then ladle into bowls and serve with lemon wedges.